.nav {
    height: 64px;
    border-bottom: 1px solid #ccc;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 99;
    background-color: #fff;
    .title {
        font-size: 17px;
        color: #2f2f2f;
        text-align: center;
        line-height: 65px;
    }
    .back-icon {
        width: 27px;
        height: 27px;
        position: absolute;
        top: 23px;
        left: 10px;
        background-image: url('./img/back.png');
        background-size: cover;
    }
}